Virtual Turbine Engine Test Bench

April 9, 2013
Innovation provides turbine engine learning solutions

Technology and innovation go hand-in-hand these days and drive much of what we do; or you can say technology drives innovation. Technology and innovation also are seen as major contributors to education and training. Many long and sometimes boring instructor-led lectures have given way to learning labs with individual computer-based training modules, virtual learning systems, and interactive educational solutions.

While cruising through the many exhibits at AirVenture 2012, a display with a small turbofan engine caught my attention. After a detailed briefing of the DGEN 380 engine and its features, I learned this compact jet engine was only one of the offerings of the French company Price Induction (PI). The offering I found more interesting was its turbine engine education solutions, one of which is the WESTT CS/BV virtual engine test bench which is based on the DGEN 380; more on the DGEN 380 later.   

The virtual test bench

Learning the principles of a turbine engine is generally accomplished in a variety of classroom settings and eventually students involved in maintenance and operation of turbine engines may find themselves in an aircraft, simulator, or perhaps a test cell in a manufacturing or engine MRO facility. Now this can be accomplished in an environmentally friendly manner; no fuel, no noise, and no exhaust.

Christine Lloyd, North American representative for PI, says, “The WESTT CS/BV is a multipurpose simulation bench which can be used for any number of educational purposes such as learning the principles of turbine engines and actually operating a turbine engine.”

The test bench console appears similar to those operating in most turbine engine test cells with one major exception; there’s no real engine. The computer systems contain software which simulates the DGEN 380’s operating behavior. The console of the test bench contains three screens; a command screen on the left where the operator has the ability to control the engine and some outside parameters such as altitude, speed, and outside air temperature; a screen in the middle which displays the engine operating instrumentation (several types of displays are available on the test bench console depending on the educational goals targeted by the user); and the screen on the right which offers a 3-D display of the DGEN 380 engine during operation.

The right hand display screen provides visualization of the engine during all phases of operation including visualization of cold and hot air flow patterns, rotation of internal components, and the speeds of the individual engine sections for virtually any flight condition programmed into the simulation. The system has the ability to zoom in and out on areas of the engine, change the angle of view, show detailed images of engine sections or components, or hide sections or components from view.

Ms. Lloyd says, “In order to simulate the most modern technologies actual full authority digital engine control (FADEC) hardware is included. The engine control unit (ECU) has the ability to calculate and control the simulated fuel mass flow according to the flight conditions chosen by the test bench operator. Engine operation is controlled mostly through a manual control; the power level angle (PLA). As PLA settings are changed, the engine (simulation) reacts just as if the engine was mounted inside an adjacent engine test cell or on an aircraft.”

The manual controls and instrumentation on the test bench provide direct access to all the necessary and simulated components such as the master switch, the mode selector for choosing engine mode (ignition, normal or crank), and to simulate flight conditions such as altitude, speed, and aircraft electrical consumption. The operator also has the ability to switch from manual controls to software controls. A wide range of failure modes can be programmed into the WESTT CS/BV to simulate a spontaneous failure or more subtle failure modes such as fuel leaks or a sensor malfunction.

Martin Vivies, the CTO of the U.S. subsidiary, says, “Behavior of the engine can be changed by changing the code in real-time. The DBM/JTAG Debug Interface (BDI) makes it possible to upload modified FADEC code onto the microcontroller located on the electronic card. This code can be changed in order for students to see how different operating scenarios affect the engine while it happens.”

Data can be recorded either as single operating points or at 25 Hz-frequency sequence meaning data is being recorded every 20 ms to be used for future calculations and research. Data includes, main engine run parameters such as engine speed rates, EGT, etc., control system regulation, thermodynamic exploration of the whole engine, aerodynamic exploration of the high-pressure stage, and dynamic schematics of the oil and fuel systems.

Other educational solutions

The turbine engine training solutions don’t end with the virtual test bench. Also offered is the WESTT SE Assembly & Disassembly Bench, a specifically designed engine work stand with documentation for full assembly and disassembly, tools and equipment, dedicated storage units and carts, and a maintenance manual; the SE-V or Validation Option which includes an electronic bay which provides the ability to operate the engine without actually providing fuel and starting it, in order to validate the engine reassembly process was correct; the WESTT BR or Real Engine Test Bench; and the WESTT HP, a high pressure spool assembly station.

Ms. Lloyd says, “The education product line has experienced rapid growth. The first DGEN 380 engine was run on a crude test bench in 2006. Two years later the first school in France expressed interest, and in 2010 the first Virtual Test Bench was installed.” Ms. Lloyd does admit it hasn’t been easy to market because it is new, but does say interest is there once people understand what the virtual test bench can do. She says, “Teachers are not the buyers and funding for major purchases by educational institutions can be difficult, so we also assist potential customers looking for research funding.”

I was curious to learn the history behind the development of the virtual test bench and Ms. Lloyd says, “The reason for development of the virtual test bench came from the need to test our own FADEC designs before installing it on actual engine prototypes. The test bench allowed us to fine-tune our FADEC with numerous tests on this virtual engine.” Currently 10 virtual test benches are installed at universities in Brazil, China, Lebanon, France, the United Kingdom, and the United States.

Headquartered in France, Price Induction SA has three subsidiaries: the USA (Atlanta), Brazil (São José dos Campos), and Germany (Berlin). More information can be found by visiting http://www.price-induction.com.